Platelet transfusion is the leading cause of transfusion related bacterial sepsis. Despite the mandated testing of platelet concentrate (PC) for contaminant bacteria, limitations in currently used testing methods continue to result in a significant number of false-negative results from systematic errors associated with sampling at times when bacterial numbers are low. This was recently underscored by the abrupt termination of the PASSPORT, a study designed to assess extending the transfusable lifespan of PCs. This occurred because a high incidence of bacterial contamination was detected even though the PC was previously tested. One approach for addressing this problem is effective testing just prior to transfusion when contaminant bacteria have had time to grow to more easily detectable numbers. BioSense Technologies proposes to continue the development of a prototype instrument for the rapid bacterial testing of PCs that is sensitive, rapid, and easy to implement - all of the criteria needed for acceptance in hospital blood banks. The technical approach is based on monitoring the stress developed by bacteria growing in PC in the presence of a chemical stressor using a novel sensing modality that assesses their absence or presence. The approach is applicable to both whole blood-derived and aphaeresis PCs and all bacterial species. Although the technical feasibility of this approach has been demonstrated, its integration into a practical instrument has not yet been done which has posed an obstacle to investment. BioSense proposes to develop a fully automated prototype instrument and to validate it through independent testing at leading hospital blood banks. PUBLIC HEALTH RELEVANCE: In the United States, bacterial contamination is detected in approximately 1 of every 2000 units of platelets produced and the overall incidence may be even higher. It is also the leading cause of transfusion related bacterial sepsis. The availability of an effective bacterial test for use just prior to transfusion will: 1) Detecting all bacterial species with high sensitivity within the same assay will provide a safer blood supply;2) Doubling the transfuseable lifespan of PC will reduce pressure on the availability of platelets and the nation's blood supply;and 3) Increase public confidence in the nation's blood supply at a time when emerging infectious diseases are continuously undermining this confidence.